//节点表
//level 1是模块，2是控制器，3是方法
+----+-------+-----------+--------+-----
| id | name  | title     | pid | level | 
+----+-------+-----------+--------+-----
|  1 | admin | 后台模块    |  0 |     1 |  
|  2 | cate  | 分类控制器  |  1 |     2 |  
|  3 | add   | 分类添加方法|  2 |     3 | 
|  4 | goods | 商品控制器  |  1 |     2 |   
|  5 | add   | 商品添加方法|  4 |     3 |   
|  6 | index | 分类展示方法|  2 |     3 | 
+----+-------+-------+--------+-------

//权限表（角色和节点的中间表）
+---------+---------+
| role_id | node_id |
+---------+---------+
|       1 |       4 |
|       1 |       5 |
|       1 |       1 |
|       2 |       1 |
|       2 |       2 |
|       2 |       3 |
|       2 |       6 |
+---------+---------+

角色表
+----+----------
| id | name   | 
|  1 | goods  |  
|  2 | cate   |  
+----+-------+--

//中间表
+---------+---------+
| role_id | user_id |
+---------+---------+
|       1 | 3       |
|       2 | 2       |
+---------+---------+

//用户表
+-----+----------+----------------------------------+
| uid | username | password                         |
+-----+----------+----------------------------------+
|   1 | admin    | 21232f297a57a5a743894a0e4a801fc3 |
|   2 | cate     | 21232f297a57a5a743894a0e4a801fc3 |
|   3 | goods    | 21232f297a57a5a743894a0e4a801fc3 |
+-----+----------+----------------------------------+








